Print substance end-of-life predictions

ABSTRACT

An example device capable of predicting print substance end-of-life (EOL) comprises a container to hold a print substance, the container comprising a refill port through which print substance is to be introduced into the container. The example device also comprises a processor to receive signals indicative of an amount of print substance introduced via the refill port. The processor is also to predict a print substance end-of-life (EOL) based on the amount of print substance introduced.

BACKGROUND

At times, devices may apply print substance to a substrate to formmarkings, including images and text. The devices may store printsubstance in containers. Predictions may be made of print substanceend-of-life (EOL) for a particular container.

BRIEF DESCRIPTION OF THE DRAWINGS

Various examples will be described below by referring to the followingfigures.

FIG. 1 is a block diagram of an example device;

FIG. 2 is a flowchart for an example method for predicting printsubstance end-of-life (EOL);

FIG. 3 is a block diagram of an example print device;

FIG. 4 is a flowchart for an example method for determining a number ofpages printable; and

FIG. 5 is flowchart for an example method for determining a number ofpages printable.

Reference is made in the following detailed description to accompanyingdrawings, which form a part hereof, wherein like numerals may designatelike parts throughout that are corresponding and/or analogous. It willbe appreciated that the figures have not necessarily been drawn toscale, such as for simplicity and/or clarity of illustration.

DETAILED DESCRIPTION

Marking substrates, such as paper, with images and text may be performedin a number of ways. For instance, different forms of print substances,such as fluid print substances, solid print substances, and printsubstances comprising combinations of fluids and solids may be used toform markings on substrates in different ways. Similarly, additivemanufacturing processes, such as 3-D printing, may comprise the layeringof particles and/or binding agents of different materials on an initialsubstrate or platform. For example, a print substance may be applieddirectly to a substrate or indirectly to a substrate. To illustrate, afluid print substance may be applied directly to a substrate by ejectingdrops of print substance to the substrate. In another example, a printsubstance comprising solids may be arranged on an application member ina desired pattern and subsequently transferred from the applicationmember to the print substrate. It is to be understood that these arenon-limiting examples of possible methods of marking substrates usingexample print substances, and other methods are contemplated by claimedsubject matter.

It should be understood, therefore, that a number of different printsubstances, such as print fluids (e.g., inks), print solids (e.g.,toners), and additive materials by way of non-limiting example, may beapplied to a print substrate to form markings thereon in a number ofdifferent ways. Print substances of different types may be stored incontainers and conveyed towards an appropriate application mechanism(e.g., for application to a substrate), such as via a print head or adeveloper unit/transfer unit, by way of non-limiting example. It isnoted that in some implementations, containers for storing printsubstance may include an integrated and/or a separate applicationmechanism. For instance, some electrophotographic (EP) print devices mayuse containers that include an integrated development unit, while othersmay use distinct containers, development units, transfer units, etc. Insome fluid print substance print devices, containers may comprise anintegrated print head and/or a print head distinct from a fluid printsubstance container.

Whatever the form of the print substance or the method of marking asubstrate, there may be a desire to estimate whether sufficient printsubstance is available, such as within a container, to complete arequested print job. More generally, there may be an interest indetermining (e.g., predicting or estimating) a number of pages printableby a print device. In some implementations, for instance, predictionsmay be made as to print substance end-of-life (EOL) such as in the formof estimations as to a number of pages printable based on amounts ofprint substance that may be available within a cartridge, estimations ofa number of dots or pixels printable per unit (e.g., grams) of printsubstance, a measure of volume in the case of additive material-basedprinting (e.g., a number of voxels producible per unit of additivematerial), etc. Such estimations may be useful to avoid commencing aprint job (e.g., an impression of a number of pages) with insufficientprint substance to complete the job. Indeed, print jobs started withinsufficient levels of print substance may result in lower quality, userfrustration and dissatisfaction, by way of example.

At times, containers may be refilled with print substance. Predictingprint substance EOL, such as in the form of estimating a number of pagesprintable, may present certain challenges after print substance refills.For example, a print substance introduced during refill may havedifferent characteristics (e.g., amount, mass, yield, charge properties,transfer properties, fusing or melting properties, durability orreliability, volatile chemical content, particle size distribution,etc.) than a print substance originally present in a container (e.g.,original print substance as opposed to refill print substance).Additionally, determining an amount of print substance introduced duringrefill, such as in units of mass or volume, may not be directlymeasurable electronically. As such, there may be a desire for a methodfor predicting print substance EOL, such as comprising a determinationof a number of pages printable, even in cases in which refill printsubstance has been introduced to a container.

Some methods for predicting print substance EOL after print substancerefill may include using an amount of print substance introduced viarefill to determine an amount of output a printing device is able toproduce, such as a number of pages, pixels, and/or voxels that will beprintable. A number of implementations capable of making such adetermination are discussed hereinafter.

FIG. 1, for instance, illustrates an implementation comprising a device100 capable of making print substance EOL predictions. One such exampledevice 100 may comprise a processor 102 and a container 104 (e.g., forstoring a print substance). Processor 102 refers to a component (or aplurality of components) capable of executing instructions andperforming logical operations. Processor 102 may comprise a generalprocessing unit or a special processing unit, such as anapplication-specific integrated circuit (ASIC), and capable of executinginstructions to enable prediction of print substance EOL. Container 104may comprise a refill port 106. Print substance may be introduced duringrefill via refill port 106 (and print substance may be conveyed out ofcontainer 104 via conveyance port (not shown in FIG. 1; see conveyanceport 308 in FIG. 3)). It is noted that though refill port 106 isillustrated by a block that is independent from the block representingcontainer 104, refill port 106 is not necessarily distinct fromcontainer 104. Indeed, in some implementations, refill port 106 may beintegrated within container 104. In another case, refill port 106 maycomprise an opening in a wall structure of container 104.

In some implementations, there may be a connection 110 (e.g., anelectrical connection, an optical connection, etc.) that may enable anexchange of signals between container 104 and/or refill port 106 andprocessor 102. There may be a desire, for instance, to communicatesignals indicative of an amount of print substance introduced via refillport 106 to processor 102, such as to enable predictions of printsubstance EOL (e.g., a number of pages printable) for device 100.

Example device 100 may comprise a container (e.g., container 104) tohold a print substance, the container comprising a refill port (e.g.,refill port 106) through which print substance is to be introduced intothe container (see e.g., the arrow in FIG. 1) And there may be a desireto predict print substance EOL, such as after introduction of printsubstance into container 104. Such print substance EOL predictions maybe accomplished using a processor (e.g., processor 102) to receivesignals indicative of an amount of print substance introduced via therefill port, and predict a print substance EOL based on an amount ofprint substance introduced.

FIG. 2 illustrates an example method 200 for predicting a printsubstance EOL based on an amount of print substance introduced viarefill. Reference is made to elements of FIG. 1 to illustrate oneimplementation of example method 200. The following discussion is not tobe taken in a limiting sense.

As illustrated at block 205, example method 200 may include receiving,via a refill port (e.g., refill port 106 of device 100 in FIG. 1) of acontainer (e.g., container 104), a print substance. In some examples,for example, a refill container holding refill print substance mayintroduce print substance into container 104 via refill port 106. If arefill container comprises a bottle of refill print substance, thebottle may connect to a refill interface of device 100 (not shown inFIG. 1; see refill interface 320 in FIG. 3) to introduce additionalprint substance into container 104 (e.g., refilling). The introducedrefill print substance may be added to remaining (e.g., original) printsubstance in container 104.

As illustrated at block 210 of example method 200, the device (device100) may determine, using a processor (e.g., processor 102 of FIG. 1),whether the received print substance comprises an authenticated printsubstance. As referred to herein, an authenticated print substance is ofa verified and/or authorized source. For example, circuitry (e.g., amemory, a processor, etc.) may be included on a refill container and maystore signals or states indicative of a source of the refill container(e.g., within a serial number) and may be used in order to authenticatethe refill container and any print substance contained therein. Inanother example case, a refill container may include identifier markings(e.g., an ID number, a serial number, bar-code, a QR code, etc.) thatmay be entered into a user interface (UI) of the device to authenticateprint substance contained therein. In another case, a physical featureof a refill container (e.g., a particular opening shape or featurethereof) that may be used to authenticate a print substance containedtherein. In some implementations, authentication may be performed byprocessor 102 (e.g., in response to execution of computer executableinstructions) based on signals received related to an identity of arefill print substance container and/or refill print substance containedtherein.

At block 215 a decision is made in response to the determination ofblock 210. For example, in response to a determination that printsubstances received at block 205 are not authenticated, example device100 may cease to predict print substance EOL, such as illustrated byblock 235 of FIG. 2. For example, device 100 may cease to predict anumber of pages printable because, for instance, device 100 may not beable to confirm print substance characteristics to enable predictions ofprint substance EOL with acceptable levels of accuracy. Furthermore,there may be a concern that non-authenticated print substances may leadto unsatisfactory print quality, damage to a developer system, or otherpotentially undesirable results. Device 100 may provide warningsinforming users of the lack of print substance EOL predictions, andpotential consequences thereof. For example, if a user sends a print jobto device 100, a warning may be displayed to inform the user that device100 may not have sufficient print substance to complete the print job.Etc.

If, on the other hand, a print substance is determined to be authentic,such as illustrated by block 210, example method 200 may advance toblock 220. In some examples, as illustrated at block 220 a determinationmay be made of an amount of print substance that has been introduced. Anamount of print substance introduced may be in terms of mass (e.g.,grams) or volume (e.g., milliliters (ml)). In some implementations, anamount of print substance introduced, such as to container 104 of FIG.1, may be determined based on an identification feature of a printsubstance refill container. For example, an example print substancerefill container may have a mechanical mechanism (e.g., a prongmechanism, such as a feature on the example substance refill containerthat interfaces physically and mechanically with a receiving interface,potentially allowing for sensing by pressure, by light, by electricalconnectivity or other means, etc.) for indicating print substance amount(e.g., in terms of mass or volume). In another example, an example printsubstance refill container may comprise an electrical mechanism forconveying information regarding print substance amount. For example, theprint substance refill container may comprise a memory in which signalsor states may be stored indicative of print substance amount stored inthe refill container. The signals or states may be fetched to determinehow much print substance is contained in the refill container. Inanother example, the identification feature may comprise anoptically-read identifier, such as a bar code or QR code, by way ofnon-limiting example, that may be read to determine an amount of printsubstance stored within the print substance refill container. In yetanother example, the identification feature may comprise an identifiermarking that may be manually entered by a user, such as including aserial number. Other example methods of determining an amount of printsubstance introduced into a container may be used, including, but notlimited to, a combination of the foregoing examples.

For example, in the case of a refill container with signals stored in amemory, the signals may be fetched and may be indicative of a mass orvolume of print substance stored in the refill container (e.g., refillcontainer contains 500 g of print substance X). Likewise, in a case ofan identification feature such as a QR code, the identification featuremay be identified (e.g., scanned by device 100 or a user) and acorrespondence may be made to a mass or volume, by way of example (e.g.,refill container recognized as refill container XYZ having a printsubstance mass of Y).

At block 225 of example method 200, a processor, such as processor 102of device 100 in FIG. 1, may execute instructions to use the determinedamount of print substance introduced to predict a print substance EOL.For example, using the amount of print substance determined to have beenintroduced at block 220, a determination may be made as to a number ofpages that may be printed (referred to herein as a number of pagesprintable) using the introduced print substance. As noted, a number ofcharacteristics of the print substance may influence a number of pagesthat may be printed per unit mass/volume of a given print substance. Insome example cases, for instance, a calculation may be made using anamount of print substance introduced in order to yield a number of pagesprintable (e.g., based on a testing methodology established by astandards organization). In an alternative case, a memory may beconsulted, such as containing a lookup table, to determine a number ofpages printable based on an amount of print substance introduced. Forinstance, X₁ grams of print substance may correspond to Y₁ pagesprintable in some cases. In another case, X₂ grams of print substancemay correspond to Y₂ pages printable. In yet another case, an amount ofprint substance may correspond to a yield value, a number of dots, orother like measure that may be used to determine a number of pagesprintable. Such yields may be determined consistent with the ISO/IEC19752 testing guidelines, by way of non-limiting example.

In some implementations, the number of pages printable for introducedprint substance may be added to a number of pages printable forremaining print substance in container 104 prior to refill. In anothercase, due for instance, to a relative difference between the remainingnumber of pages printable before refill (e.g., which might be on theorder of tens or hundreds) and the number of pages printable due torefill print substance introduced (e.g., which might be on the order ofthousands or tens of thousands), the device may instead use the numberof pages printable based on the refill print substance introduced.Whatever the particular approach that might be taken to predict printsubstance EOL (e.g., determine a number of pages printable), the device(e.g., example device 100 of FIG. 1) may transmit signals indicative ofthe determined number of pages printable, such as shown at block 230 ofFIG. 2. For example, signals indicative of the determined number ofpages printable may be transmitted, such as for storage in a memory ofcontainer 104, to a display of a device, a connected computing device, aserver on a private or public network, etc. In a case in which printsubstance is automatically transmitted to refill print devices (e.g.,based on consumption of print substance), a server may periodicallyreceive signals indicative of a determined number of pages printable.Based on those signals, refill print substance may be sent to enableprint substance refill of device 100, such as to avoid down time. It maybe desirable, therefore, as indicated at block 230, to transmit signalsindicative of a number of pages printable.

Another implementation for predicting print substance EOL is shown inFIG. 3. Example print device 300 may comprise a number of componentsthat may be similar or analogous to those of example device 100illustrated in FIG. 1. For instance, print device 300 may comprise aprocessor 302 and a container 304. Container 304 may comprise a refillport 306 (e.g., similar to refill port 106 in FIG. 1) and a conveyanceport 308. Refill port 306 and/or conveyance port 308 may be in the formof an opening in container 304, may comprise a physical structureextending out of container 304 (e.g., a mouth or neck), and/or may beintegrated into container 304 (e.g., forming unitary components) or maybe discrete from container 304 (e.g., forming an attachable/detachablecomponent), by way of non-limiting example. Example print device 300 mayalso comprise a refill interface 320 connected to refill port 306.Refill interface 320 may comprise mechanical and/or electrical elements,such as to facilitate authentication of print substance and/ordetermination of amounts of print substance introduced to container 304.For instance, in cases in which refill container 322 comprises a memory(e.g., memory 312 c), refill interface 320 may comprise circuitry toreceive signals indicative of amounts of print substance from memory 312c and/or signals indicative of authenticity of print substance, by wayof example. In cases in which refill container 322 comprises otheridentification features 324, such as mechanical identification features(e.g., a prong or other structural element), refill interface 320 maycomprise mechanical elements that may interact with the identificationfeatures of refill container 322. For instance, in some cases, refillcontainer 322 may comprise an identification feature 324 including aparticular pattern or shape of mechanical elements, such as a prong. Theidentification feature 324 may interact with refill interface 320 (e.g.,the prong may interact with a trigger of refill interface 320) toindicate an authenticity of print substance and/or an amount of printsubstance contained within refill container 322, by way of example. Forinstance, refill interface 320 may comprise a plurality of triggers, anda particular trigger activated by identification feature 324 may providean indication of an authenticity and/or an amount of print substancecontained in refill container 322. A combination of mechanical andelectrical elements may be used to determine print substanceauthenticity and/or an amount of print substance contained in refillcontainer 322. For instance, in some example cases, an indicator ofauthenticity may be provided using an electrical element, while anamount of print substance introduced may be provided using a mechanicalelement. Etc. It is noted that while illustrated as distinct components,refill interface 320 and refill port 306 may be a unitary component insome implementations.

There may be a desire to store a number of pages printable on container304, such as to allow container 304 to be removed from print device 300and installed in a different print device while still being able toprovide a number of pages printable to the different device. Thus, insome implementations, container 304 may also comprise a memory 312 b,which may be capable of storing a number of pages printable or othermeasure of print substance EOL predictions (e.g., dot or pixel countpredictions). For example, upon a determination of a number of pagesprintable, the value may be stored in memory 312 b. The number of pagesprintable stored in memory 312 b may be updated periodically orcontinually, for example.

Example print device 300 may also comprise a print substance applicator326. In some cases, for instance, print device 300 may form a latentimage on a photoconductive element and subsequently transmit printsubstance, such as in the form of the latent image on thephotoconductive element, to a print substrate. The collection ofcomponents used to form an image on a substrate may be represented byprint substance applicator 326. In another case, for instance, printdevice 300 may apply print substance directly to a print substrate, suchas by depositing a number of dots of print substance. Again, in thiscase, the collection of components to enable depositing dots of fluidprint substance on a substrate may be represented by print substanceapplicator 326. Of course, other methods of applying print substance arecontemplated by claimed subject matter and may be enabled usingdifferent variations of print substance applicator 326. Whatever theparticular method, print substance may be conveyed via conveyance port308 and conveyance channel 332 (which, similar to refill interface 320and refill port 306 may comprise distinct or unitary components) toprint substance applicator 326. For instance, in cases in which printsubstance comprises fluids, conveyance channel 332 may comprise a tubeor other such structure via which fluids may be conveyed, such as usingpressure, etc. In cases in which print substance comprises solids,conveyance channel 332 may also include conveying and/or agitatingmechanisms, such as augers, to transmit print substance to printsubstance applicator 326. Etc.

Example print device 300 may comprise other components to facilitateauthentication of a print substance, determination of an amount of printsubstance introduced, prediction of a print substance EOL (e.g., anumber of pages printable) based on an amount of print substanceintroduced, etc. For instance, a memory 312 a of print device 300 may bein communication (e.g., electrical communication, optical communication,etc.) with other components of print device 300 (e.g., such as via abus) and may store instructions, data, and other such information toenable determinations such as those discussed above in relation toexample method 200 (and also those to be discussed hereinafter inrelation to FIGS. 4 and 5). Memory 312 a (and also memory 312 b and 312c) may comprise volatile and non-volatile memory such as RAM memory,flash memory, solid state memory, resistive memory, and magnetic memoryby way of example.

Example print device 300 may also comprise an indicator 316. Anindicator 316 may provide an indication that may be readable by a user,such as a human-readable indication. For example, one such indicator 316may comprise a gas gauge-style indicator comprising an arm or needlethat may move relative to markings to indicate a print substance EOL,such as in terms of a number of pages remaining. Another exampleindicator 316 may comprise lights (e.g., an array of LEDs) capable ofindicating a number of pages printable, a number of pages used, etc. Forinstance, an array of lights may light up or turn off to demonstrate arange of possible pages printable values and/or a full or empty natureof a container. Thus, indicator 316 may enable notification of a numberof pages printable and/or a state of a container of print substance(e.g., full, empty, etc.).

Example print device 300 may also comprise a display 318. Exampledisplays may include LED displays, LCD displays, OLED displays, andprojection displays, by way of non-limiting example. Display 318 may becapable of providing information to users, providing an interface withwhich users may be capable of interacting (e.g., a user interface (UI)),etc. Example information that display 318 may capable of providing mayinclude information regarding a connection between print device 300 andan external device, such as server 330 (e.g., electrical connections,optical connections, RF connections, etc.). For example, display 318 maybe capable of informing users that a connection exists between printdevice 300 and server 330 (such as via network 328), that a number ofpages printable is transmitted from print device 300 to server 330 viathe connection, etc. And in some cases, display 318 may be capable ofdisplaying information received from server 330 via the connection. Forexample, display 318 may be capable of providing status informationregarding refill print substance being sent in response to signalsreceived at server 330 from print device 300. For instance, in a case inwhich print device 300 notifies server 330 of a low number of pagesprintable, server 330 may enable transmission of refill print substancefor print device 300. Server 330 may also transmit signals to informprint device 300 of refill print substance, may provide reminders tointroduce the refill print substance into container 304, and/or mayprovide instructions to facilitate such refilling of print substance, byway of example.

In some implementations, network controller 314 may enable transmissionand reception of signals between server 330 and print device 300.Similar to other components of print device 300, network controller 314may be in communication with processor 302, such as via a bus, to allowsignals to be received from server 330, decoded by network controller314, and transmitted to processor 302 for handling. Similarly, signalsfrom processor 302 may be received at network controller 314 via a bus,encoded for transmission, and transmitted via network 328. Of course,these are but examples and other analogous components may be used toenable signal exchange without limitation.

With the foregoing example components in mind, an example print device300 is described, including example operation thereof to enableprediction of print substance EOL. For instance, an example print device300 may comprise a refill interface 320 and a container 304 to hold aprint substance. Container 304 may comprise an input port, such asrefill port 306, in communication with refill interface 320. Container304 may also comprise an output port, such as conveyance port 308, viawhich print substance may be conveyed. Print device 300 may alsocomprise a processor 302 to receive signals indicative of authenticatedprint substance introduced to container 304 via refill interface 320.Processor 302 may also receive signals indicative of an amount ofauthenticated print substance introduced via refill port 306. Thesignals indicative of the amount of print substance introduced may bereceived via refill interface 320. Processor 302 may also determine,using the amount of authenticated print substance, a number of pagesprintable. For instance, processor 302 may determine a number of pagesprintable using an amount of authenticated print substance received viarefill interface 320, and may also use a number of pages printable basedon print substance remaining in container 304 prior to refill. Thedetermined number of pages printable may be indicated via display 318.The determined number of pages printable may also (or alternatively) beindicated via indicator 316. Indicator 316 may comprise a human-readablegauge, for instance.

As noted above, in some implementations the signals indicative of theamount of print substance introduced may be representative of an amountof print substance measured in grams. A relationship between amounts ofprint substance measured in grams and numbers of pages printable may beused to determine a number of pages printable based on the amount ofprint substance introduced. In another implementation, an amount ofprint substance introduced to container 304 via refill interface 320 maybe expressed in mi. And a relationship between ml of print substance anda number of pages printable may enable determination of a number ofpages printable based on an amount of print substance introducedexpressed in ml. Of course, other implementations are contemplated byclaimed subject matter.

Operation of example print device 300 can be described by reference toFIGS. 4 and 5. FIG. 4 illustrates an example method 400 for determininga number of pages printable based on an amount of introduced refillprint substance. At example block 405, signals may be receivedindicative of refill print substance identification. For example, asshown in FIG. 3, an identification feature 324 may be used to enabledetermination of authenticity of print substance. In some cases, thismay comprise identification of a print substance refill container 322.As noted, signals may be stored in a memory 312 c of refill container322 indicative of an identification. The stored signals may be fetchedby print device 300 to determine an authenticity of the print substance.The identification may also be conveyed by markings, such as a physicalpattern (bar code, QR code, etc.) or human-readable markings (e.g., aserial number), such as may be formed on refill container 322.Identification may also be conveyed by a physical shape ofidentification feature 324. Other approaches are also contemplated byclaimed subject matter, and the foregoing examples are merely presentedby way of example.

If it is determined that the refill print substance is not authentic,then, as shown by block 410, example method 400 may proceed to block430, indicating an end. In some implementations, ending method 400 atblock 430 may correspond to ceasing to provide pages printablepredictions (see, e.g., the foregoing discussion of block 235 of FIG.2). If, on the other hand, it is determined that the refill printsubstance is authentic, then method 400 may proceed to block 415, todetermine a number of pages printable. As noted above, determining anumber of pages printable may comprise determining an amount of printsubstance introduced. Thus, for instance, if it is determined that Xgrams of print substance is introduced via refill port 306, then anumber of pages printable may be determined (e.g., based on acorrespondence between grams of print substance and numbers of pagesprintable). For example, in some implementations, 500 g of printsubstance may yield approximately 20,000 pages printable, by way ofnon-limiting example.

At block 420, the determined number of pages printable may be displayedand/or indicated. For example, print device 300 of FIG. 3 may provide anindication of a number of pages using indicator 316, such as ahuman-readable gauge. In another example case, a number of pagesprintable may be displayed, such as using display 318.

At block 425, the number of pages printable may be stored, such as inmemory 312 b of FIG. 3.

Moving on to FIG. 5, an example method 500 illustrates additionalaspects of operation of example print device 300, such as fordetermining a number of pages printable. For instance, as shown at block505, a print device, such as print device 300 of FIG. 3, may be capableof receiving signals indicative of an amount of print substanceintroduced to a container. For example, refill interface 320 and refillport 306 may enable a determination of an amount of print substanceintroduced to container 304. In some cases, for example, signalsindicative of an amount of print substance introduced to container 304may be sent to processor 302.

At block 510, a number of pages printable may be determined based on theamount of print substance introduced. For example, if the signalsindicative of the amount of print substance introduced arerepresentative of an amount of print substance measured in grams, thenumber of pages printable may be determined based on a relationshipbetween grams of print substance introduced and numbers of pagesprintable. Etc.

At block 515, the determined number of pages printable based on theintroduced refill print substance may be added to a remaining number ofpages printable for the container. For example, if it is predicted that1000 pages printable remain prior to refill, and an amount of printsubstance introduced corresponds to 10,000 pages printable, then, asillustrated at block 515, 11,000 pages may be determined to be a totalprint substance EOL prediction. As noted above, this value may be storedto memory 312 b, may be transmitted to indicator 316, may be transmittedto server 330, etc.

In view of the foregoing, then, an amount of print substance introducedto a container may be used to predict a print substance EOL, such as interms of a number of pages printable.

What is claimed is:
 1. A device comprising: a print substanceapplicator; a processor; a container comprising a refill port throughwhich print substance is to be introduced into the container; and arefill interface connected to the refill port, the refill interface to:couple with a refill container that is external to the device; receiveprint substance from the refill container; receive a signal from therefill container indicative of an amount of print substance received;and transmit the signal received from the refill container to theprocessor, wherein the processor is to: receive the signal indicative ofthe amount of print substance from the refill interface; and predict aprint substance end-of-life (EOL) based on the received signal.
 2. Thedevice of claim 1, wherein the processor is further to determine whetherprint substance received via the refill interface comprisesauthenticated print substance.
 3. The device of claim 2, wherein theprocessor is further to disable prediction of the print substance EOLbased on a determination that print substance received via the refillinterface comprises unauthenticated print substance.
 4. The device ofclaim 2, wherein the processor is further to determine whether the printsubstance received via the refill interface comprises authenticatedprint substance based on a signal received from the refill container. 5.The device of claim 4, wherein the signal received from the refillcontainer used to indicate the authenticity of the print substancecomprises a physical feature of the refill container, an electricalsignal, or an identification marking of the refill container.
 6. Thedevice of claim 1, wherein the to be predicted print substance EOLcomprises a determination of a number of pages printable and wherein theprocessor is further to transmit the to be determined number of pagesprintable.
 7. The device of claim 6 further comprising a display toindicate the to be determined number of printed pages.
 8. The device ofclaim 6 further comprising a human-readable gauge to indicate the to bedetermined number of printed pages.
 9. The device of claim 1, whereinthe signal indicative of the amount of print substance received isrepresentative of an amount of print substance measured in grams and theto be predicted print substance EOL is to be determined based on arelationship between grams of print substance and numbers of pagesprintable.
 10. The device of claim 1 further comprising a memoryarranged on the container, wherein the processor is further to store asignal indicative of the to be predicted print substance EOL.
 11. Thedevice of claim 1, wherein the signal received from the refill containercomprises a mechanical signal, an electrical signal, or anidentification marking of the refill container.
 12. The device of claim11, wherein the mechanical signal comprises a prong mechanism.
 13. Thedevice of claim 1, wherein the processor is further to predict the printsubstance EOL based on the amount of print substance received and basedon an amount of print substance remaining in the container prior to thereceiving of the print substance from the refill container.
 14. A printdevice comprising: a refill interface to interact with a refillcontainer that is external to the print device and to receive a printsubstance from the refill container; a container to hold the printsubstance, wherein the container comprises an input port incommunication with the refill interface; and a processor to: receive afirst signal from the refill interface to enable authentication of theprint substance introduced to the container via the refill interface;receive a second signal from the refill interface indicative of anamount of the authenticated print substance introduced via the refillinterface; and determine, based on the received second signal, a numberof pages printable by the print substance in the container, wherein thefirst signal and the second signal are received by the refill interfacefrom the refill container.
 15. The print device of claim 14 furthercomprising a network controller to transmit the to be determined numberof pages printable by the print substance to an external device.
 16. Theprint device of claim 14, wherein the to be determined number of pagesprintable by the print substance in the container is to be determinedbased on a relationship between print substance amounts and numbers ofpages printable by print substance.
 17. A method comprising: receiving,via a refill port of a container of a print device from an externalrefill print substance container, a print substance; determining, usinga processor, whether a first signal received from the external refillprint substance container indicates that the received print substancecomprises an authenticated print substance: in response to adetermination that the received print substance comprises anunauthenticated print substance, ceasing to determine a number of pagesprintable by the print substance in the container; and in response to adetermination that the received print substance comprises anauthenticated print substance: determining, using the processor, anamount of the print substance introduced to the container based on asecond signal received from the external refill print substancecontainer; determining, using the processor, a number of pages printablebased on the determined amount of the print substance introduced to thecontainer; and transmitting a signal indicative of the number of pagesprintable.
 18. The method of claim 17, wherein the first signal receivedfrom the external refill print substance container is obtained byfetching the first signal stored on a memory of the external refillprint substance container.
 19. The method of claim 17 further comprisingstoring the signal indicative of the number of pages printable to amemory of the container.